The invention relates to a stacked type plate heat exchanger. A German patent publication DE 4 314 808 A1, for example, discloses a plate heat exchanger designed as an oil/coolant cooler. This plate heat exchanger comprises a multiplicity of trough-shaped heat exchanger plates stacked one on top of the other. The peripheral edges of the exchanger plates bear on one another and are sealingly soldered together. At the same time, all the heat exchanger plates have the same shape. Flow ducts are formed between the plates, one flow duct being assigned to an oil circuit and another flow duct to a coolant circuit, alternately in each case. Provided in the heat exchanger plates are recesses or openings, through which the heat exchanger media are supplied or are conveyed further to the following flow ducts.
This known plate heat exchanger is designed on the principle of identical parts and is therefore extremely simple in construction and cost-effective in production. In view of the identical design of the throughflow cross sections and the absolutely identical type and number of the respective flow ducts, a sufficient heat transmission capacity is afforded only when the mass flow and volume flow of the two heat exchanger media are approximately the same. This is the case, for example, when the plate heat exchanger is used as an oil/coolant cooler.